HHRG (Home Health Resource Group)

The HHRG for a period comes from five inputs combined: admission source (community or institutional), timing (early or late), clinical grouping (one of 12 groups from the principal diagnosis), functional impairment level (low, medium, or high from OASIS items), and comorbidity adjustment (none, low, or high from secondary diagnoses). The term predates PDGM: under the legacy 60-day prospective payment system there were 153 HHRGs driven heavily by therapy utilization. Since January 2020 the term refers to the 432 PDGM groups, and therapy volume plays no role in the assignment.

The two terms are often used interchangeably, but they sit at different layers. The HHRG is the payment group itself, the classification. The Health Insurance Prospective Payment System (HIPPS) code is the five-character code that represents that group on the Medicare claim, reported on the revenue code 0023 line. Grouper software translates the OASIS assessment and coded diagnoses into the HHRG and outputs the HIPPS code for billing. When billers talk about what the period grouped to, they usually cite the HIPPS code; when analysts model payment, they think in HHRGs and weights.

Each HHRG maps to a case-mix weight published annually by CMS. Expected payment is the national standardized 30-day base rate multiplied by the weight, with the labor portion adjusted by the wage index for the patient's location. Two adjustments can override the full HHRG payment: if visits fall below the group's Low Utilization Payment Adjustment (LUPA) threshold, the period pays per visit instead, and partial episode payment proration applies in transfer and discharge-with-readmission situations. Weights were recalibrated in the CY2026 final rule using CY2024 data, so the same HHRG can pay differently from one year to the next.

HHRG accuracy is a documentation and coding exercise, not a billing one. The levers are upstream: a principal diagnosis specific enough to group cleanly, secondary diagnoses that capture documented comorbidities, and OASIS functional items that reflect the patient's actual ability. Strong agencies run the grouper before the claim, compare expected HHRG against what Medicare pays on the remittance, and investigate mismatches, since CMS recodes timing and admission source from its own claims history. Tracking average case-mix weight by team or branch also surfaces drift, whether from undercoding or from assessment inconsistency.